Norvel 074

[Casey]

My Norvel 074 has arrived in the mail. But the head is screwed on very tight. Shall I just use increasing force to loosen the head or should I heat up the head?

[Doug Moon]

Why do you want to take the head off?

[Casey]

The break in advice from Norvel's operating instructions are, "Before starting it with fuel, you MUST first break it in cold: remove the head and a glow plug, inject no more than 1/4 teaspoon of oil into the intake and the same to the cylinder and spin the crankshaft with a starter for one or two minutes

[Larry Renger]

Heat the fins, not the head!

[dave siegler]

The norvel has a head clamp like a the other smaller ones, it can be tight from the factory, and you have to take it off to get the plug out. 

support the case well and use a little heat and the proper slotted wrench.  Bolt it onto a test stand 

flooded 074 have been known to bed a rod on a stater its a great engine, just watch out for that. 

[Fredvon4]

STOP !! HARD STOP

Norvel and the line of engines are designed to be tight from the get go....back about 10 years SIG sold them as well as others.... too many were returned as defective...WILL NOT START!

NV changed instructions to the BS spin with a drill/oil nonsense....this does work BTW, but you will soon be back to NV for a new piston and liner...

If you want to wear OUT your piston liner that is on you...Break in is all about normalising mating surfaces, heat cycling, work hardening, and always demands fuel running and HEAT...

You ever hear Ford tell a new owner to take out the plugs and run the starter for 5 min before starting?

My method began after Rusty K had issues starting his first NV ...He then used a Cox Low comp head, three shims, and a heat gun on the head... dang thing lit off and scared him near into a laundry problem....compared to a Cox TeeDee a new NV .049 will fire and go super sonic in .035 sec

I had been starting and running Nelson N36c engines a bit, so the first NV start did not surprise me that much

I, through Ken Cook, also learned that many NV engines come with a too tight fit Crankshaft to case...so that is where I learned how to diamond polish to high mirror finish with 6M, 3M and then 1 Micron pastes.

I firmly believe on ALL modern engines that have the exceptionally tight TDC fit (cold) Never hand flip ---and certainly do not ever slow turn to TDC and stop... the clearance is ZERO! Any or all lube will be displaced (cold) and the next cold movement will put a serious load on the rod journals as the piston is STUCK at TDC

I know that heat gun the head and they start just fine

[bob whitney]

if u are still going to remove the head which u will need to do if u ever change the plug,  as Larry said ,heat the cyl so it will expand away from the head

[Bill Adair]

Fred,

Finally, another knowledgeable user confirms that the NV "Cold break-in" instructions" are TOTAL BS, and should be ignored!!! Who ever wrote that in the instruction sheet should be sued, by all the new owners who ruined perfectly good engines by scrubbing away some of the new ceramic coating!

I've been saying for years that "cold spinning with a drill press, or starter" is absolute crap, and can ruin or damage a new ceramic engine in very short order. Unfortunately, that false information keeps coming back to haunt us. People who actually know anything about ceramic p/c technology, would never recommend such nonsense!

The only thing I might add to your message, is that a smaller prop is also recommended for initial runs. The whole idea is to get the engine up to operating temperature ASAP!!!

Bill

[dave siegler]

1) after years of using nirvels, don't use the break in method!!!!!!

2) Still take the head off or at least crack it loose then re-tighten it.    If it is on a plane you wont get if off then


 My breakin instructions for norvels. 

Put it on a test stand with a slightly smaller prop on it.  for 074's i used and old top flight wood 6x3 

Blast the head with a paint strip heat gun and it will loosen up a little, it will be almost smoking hot. 

hand start the engine if you can or carefully with a starter.  , careful not to flood it. 

then run it fast but not lean  run for about 3 minutes. 

let it cool and repeat do that 4-5 times.  and you are ready to fly. 

[Casey]

Thanks guys for your input. I really appreciate it. I got this bit of advise (reproduced in the paragraph below) to be done before running in the engine from one of the threads in the forum. Does it enhance the piston liner seal?

Tape the drive washer to the case where the piston is just covering the port. Fill the cylinder with straight castor oil, lightly screw the head on and leave it sit soaking for at least a day. The metal is porous and the castor oil goes into it.

[dave siegler]

Thanks guys for your input. I really appreciate it. I got this bit of advise (reproduced in the paragraph below) to be done before running in the engine from one of the threads in the forum. Does it enhance the piston liner seal?

Tape the drive washer to the case where the piston is just covering the port. Fill the cylinder with straight castor oil, lightly screw the head on and leave it sit soaking for at least a day. The metal is porous and the castor oil goes into it.

While this cant hurt, I don't do it.  not sure that castor penetrates much over a day. 

[Fredvon4]

One could argue that a Iron liner and sintered metal piston might "absorb" some micron level lube

It certainly can NOT hurt to soak in oil

I just have a hard time believing this step is necessary--- considering most engines leave the MFG lightly OILED before packaging...I do not recall ever opening any new in box engine that was not slightly lubed....IE: Bare metal to metal dry.....

Not all Norvel's are Revlite (ceramic) but they ALL have some post machining chroming, nitriding, or other hardening methods

[RknRusty]

The break in advice from Norvel's operating instructions are, "Before starting it with fuel, you MUST first break it in cold: remove the head and a glow plug, inject no more than 1/4 teaspoon of oil into the intake and the same to the cylinder and spin the crankshaft with a starter for one or two minutes

NO NO NO NO!
What they all said is right. I've written an extensive Norvel break-in post somewhere around here and that's one of the DUMBest things NV has ever advised new engine owners to do.

I sometimes put a Cox Babe Bee head on them to make the first crank easier... Come to think of it, I bet that won't work on an .074. But you can stack a bunch of head washers(5 or 6) to accomplish the same thing. After the first run, I put the Norvel head back on and never look back.

Run it up fast right away because it needs heat immediately for the piston/liner fitment to shape up. Don't cook it, but run it peak with a few brief rich back-downs just to be safe. My thread may be in the engine forum rather than the open forum. Or maybe in the 1/2A forum. Should be easy to search. Try using the Google search option.
Rusty

P.S.
Don't be cold flipping this engine through TDC before it's been run. I know it's hard to resist, but Don't.
Hope we caught this in time.

[Casey]

Thanks, everyone for your replies

[RknRusty]

Good luck, Casey. Let us know how it goes.
Rusty